Wednesday, August 28, 2013

St Nicholas Abbey Fracture Fixation Pin Breaks


The horizontal steel pin (top of radiograph, red arrow) was designed to help the injured Thoroughbred bear weight in spite of the fracture in his pastern. This pin, as you can see, is broken and had to be removed. (photo provided by Coolmore Stud)
An important announcement from Coolmore Stud was released today. Coolmore has been judiciously reporting both the good and bad news throughout the ordeal of a fractured pastern suffered while galloping to multiple Group I winner and stud prospect St Nicholas Abbey.


The horse was injured during a routine training gallop at trainer Aidan O'Brien's Ballydoyle training facility in Ireland and has been recovering at Fethard Equine Hospital, nearby in Tipperary.

Coolmore's announcement:

A major complication in St Nicholas Abbey’s recovery arose on Monday evening as he appeared a little uncomfortable.

Radiographs showed the steel weight-bearing pin in his cannon bone had broken and after consultation, the surgeons decided to take it out. The damaged pin can be clearly seen on the radiograph (view here).

This procedure was done Monday night, the leg has been re-cast and St Nicholas Abbey is now bearing weight on the fractured leg.

This development has come sooner than we would have ideally liked, so the next week is a very tentative period for us.

This morning St Nicholas Abbey is comfortable and is walking as well as can be expected. His temperament and demeanour are a tremendous plus both for him and the team treating him.

(end of Coolmore announcement)

As readers of this blog or fans of St Nicholas Abbey will know, the colt's fracture treatment was complicated by colic early in his recovery, and it was necessary to perform colic surgery. The colt's condition has benefited from the consultation of two American veterinarians: surgeon Dean Richardson, DVM of the University of Pennsylvania's New Bolton Center, who is an orthopedic specialist, and internist Dr. Nathan Slovis of Hagyard Equine Medical Institute in Kentucky.

Transfixation-equipped casts are commonly part of an overall optimum recovery program designed for horses with limb fractures.

One of the benefits of the fixation pin is that it allows the horse to bear weight on both limbs. Overloading the "good" leg is a common complication and may lead to a condition known as "support limb" laminitis.

Support limb laminitis: always a risk


A horse with a fresh fracture repair at Cornell University College of Veterinary Medicine. (Hoofcare Publishing file photo by Michael Wildenstein)

In 2011, Virgin, Goodrich and Baxter presented a paper at the American Association of Equine Practitioners Convention after reviewing case histories of injured horses surgically fixated with pins.

The authors found that 12 percent of all horses treated with leg casts developed support limb laminitis. They reported that horses with higher body weight and horses that were required to wear casts for a longer time were more likely to develop support limb laminitis.

Protocols exist in some equine hospitals for the preventive, proactive support of the "good" foot as soon as the surgery is done. Many limbs in cast become "longer" than the untreated limb, and some form of elevation or equalizing of the good foot can be helpful, as can be extra sole and frog support.

In 2011, Texas farrier Austin Edens published a case study on The Hoof Blog detailed his use of a clog screwed to a horse's shoe to equalize the height of the good limb in comparison to an injured limb.

The mechanism behind support limb laminitis will be one of the topics in the scientific session of the International Equine Conference on Laminitis and Diseases of the Foot in West Palm Beach, Florida from November 1-3, 2013. Drs van Eps of the University of Queensland and Belknap of The Ohio State University will present their latest work on the condition that complicates surgeons' efforts to help injured horses.

There is no mention of support limb laminitis by Coolmore at this time and there is no reason to expect that St Nicholas Abbey will develop the condition. Coolmore's statement that the horse was able to bear weight on his injured leg after the transfixation pin was removed is encouraging.

• • • • • • • • 

To learn more about support limb laminitis, please read:
Incidence of Support Limb Laminitis in Horses Treated With Half-Limb, Full-Limb, or Transfixation Pin Casts: A Retrospective Study of 113 Horses (2000 –2009) by Virgin, Goodrich, and Baxter in the Proceedings of the American Association of Equine Practitioners Convention 2011

On the Case with Austin Edens: Engineering Prevention of Support Limb Laminitis with a Removable Clog Screwed to a Shoe


Supporting limb laminitis: The four important ‘whys’ by James Orsini, in the Equine Veterinary Journal, November 2012.

Click for more information about plastinated anatomy models.


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